Methods for measuring amounts of energy available from banksia inflorescences

Several methods have been used to remove nectar from banksia inflorescences to measure amounts of energy available, but these methods have been poorly described in the literature. Each method has advantages and disadvantages with respect to the proportion of nectar removed and the time taken to remove nectar. Power‐driven aspirators probably remove the most nectar, followed by syringes and capillary tubes. However, it often takes more than 20 min to sample an inflorescence using these methods. Centrifuging inflorescences by placing them in plastic bags and swinging them by hand on a rope takes only about 5 min anil allows many more inflorescences to be sampled per time. Centrifuging. however, removes only about 70% of the nectar so that the benefits gained by faster sampling are countered by reduction in accuracy. Nevertheless, amounts of nectar extracted by centrifuging provide a reliable index of the amounts present, and so it is possible to make Qualitative comparisons of inflorescences sampled at different times, from different locations, or from different experimental treatments.